3rd one ( not 20 characters so ASHWDHWHEIUCNEJEIH)
<em>10 minutes</em>
- Step-by-step explanation:
<em>24h = 24x60min = 1440min
</em>
<em>
</em>
<em>5 sec ............. 12 min
</em>
<em>x sec ..........1440 min
</em>
<em>x = 1440*5/12 = 600 sec = 10 min</em>